Resistant bacteria have emerged and established themselves worldwide as a threat to the favourable outcome of common infections in community and hospital settings. Beta lactamase production by several gram negative and gram positive organisms is perhaps the most important single mechanism of resistance to penicillins and cephalosporins. ESBL and AmpC beta lactamases are typically associated wit...

Antimicrobial resistance (AMR) occurs when microorganisms fail to respond the therapeutic onslaught of antibiotics. Extended-spectrum beta-lactamase (ESBL) and AmpC enzymes are important AMR mechanisms that erode efficacy Here, we report on detection susceptibility ESBL- AmpC-producing bacteria from livestock poultry environments. Bacteriological molecular biology tools were used for isolation ...

A clinical strain of Proteus mirabilis (CF09) isolated from urine specimens of a patient displayed resistance to amoxicillin (MIC >4,096 microg/ml), ticarcillin (4,096 microg/ml), cefoxitin (64 microg/ml), cefotaxime (256 microg/ml), and ceftazidime (128 microg/ml) and required an elevated MIC of aztreonam (4 microg/ml). Clavulanic acid did not act synergistically with cephalosporins. Two beta-...

Klebsiella pneumoniae is a major cause of nosocomial infections. Emergence of antibacterial resistance and production of beta-lactamases are responsible for the frequently observed empirical therapy failures. The aim of this study was to determine the presence and the prevalence of extended spectrum beta-lactamases (ESBLs) and AmpC beta-lactamases in clinical isolates of K. pneumoniae in Kerman...

We isolated five clinical strains (three Proteus mirabilis and two Klebsiella pneumoniae) with beta-lactam resistance phenotypes consistent with production of an AmpC-type beta-lactamase. The predicted amino acid sequences of the enzymes were typical of class C beta-lactamases. The enzymes were identified as CMY-2, CMY-4 and a new CMY-variant beta-lactamase, CMY-12. The AmpC beta-lactamases fro...

abstract        background and objectives: pseudomonas aeruginosa is the most frequent opportunistic pathogen isolated from the sputum of patients with cystic fibrosis (cf). resistance to β -lactam antibiotics may arise from over expression of the naturally occurring ampc cephalosporinases or acquired extended-spectrum β-lactamases (esbl). the aim of this study was to determine the antibiotic r...

BACKGROUND Enterobacteriaceae producing ESBL and AmpC enzymes can be associated with failure of antibiotic therapy and related morbidity and mortality. Their routine detection in microbiology laboratories is still a problem. The aim of this study was to compare the sensitivity of selected phenotypic methods. MATERIAL/METHODS A total of 106 strains of the Enterobacteriaceae family were tested,...

In competition assays for radiolabeled penicillin, penicillin-binding proteins (PBPs) 4, 7a, and 7b showed very high affinities for strong inducers of AmpC beta-lactamase. Loss of PBP 4 resulted in diminished inducibility. This suggests that if PBPs are involved in induction of AmpC beta-lactamase, there is probably a redundancy in function among the different PBPs.